Servo-Driven Press Gear with Variable Transmission Ratio

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Solution Overview

Problem

Mechanical forming presses have complex structures with numerous components, limiting flexibility and efficiency in forming, punching, and embossing processes.

Innovation Solution

A mechanical forming press with a press gear that mechanically couples a press ram to an electric servo motor drive, featuring a continuously variable transmission ratio between the servo motor's drive shaft and the press ram's output shaft, allowing for flexible ram stroke control and reduced component count through a drag crank mechanism and central counter gear arrangement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a conventional mechanical forming press structure is used, then the press can perform forming operations, but the structure becomes complex with numerous components

Engineering Contradiction:
Improvestructure complexityVSAvoidflexibility in forming processes
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The press gear is designed with a continuously variable transmission ratio that can be adjusted to provide different speed profiles for the press ram, enabling the same mechanical structure to adapt to various forming, punching, and embossing operations with different technological requirements, thereby achieving multi-functionality without increasing component count

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The press gear incorporates a variable transmission ratio mechanism that allows dynamic adjustment of the transmission characteristics during operation, enabling optimization of the press ram speed profile for different forming processes while maintaining a compact mechanical structure

Inventive Principle:
Principle #15Dynamics

2Productivity

If the press ram operates at high speed, then productivity increases, but impact speed and noise emissions increase causing tool wear

Engineering Contradiction:
Improveforming speedVSAvoidimpact speed and noise
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The press gear enables continuous variation of the transmission ratio, allowing optimization of the press ram speed profile by adjusting parameters such as the crank radius and connecting rod length to achieve lower impact speeds at bottom dead center while maintaining high overall productivity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The press gear utilizes periodic variation of the transmission ratio during the ram stroke cycle, providing accelerated motion during non-forming portions of the stroke and reduced speed during the forming operation, thereby separating high-speed motion from high-impact contact

Inventive Principle:
Principle #19Periodic action

3Object-generated harmful factors

If the transmission ratio is increased in the forming area, then the press ram slows down reducing impact and noise, but the working distance before bottom dead center decreases

Engineering Contradiction:
Improveimpact speedVSAvoidworking distance
Core Design Contradiction:
Object-generated harmful factorsVSLength of moving object

Solution Approach 1:

The variable transmission ratio mechanism allows dynamic adjustment of the speed profile along the ram stroke, enabling extended working distance at high speed followed by gradual deceleration in the forming area, optimizing both productivity and tool life

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design enhances flexibility in forming processes, reduces noise and wear, and extends tool service life by maintaining constant servo motor speed, achieving lower impact speeds and increased working capacity with fewer components.

Implementation Method 1

The output shaft is arranged eccentrically to the counter gear and coupled to the counter gear via a drag crank

Methodology Applied
Scientific EffectEccentric mechanism: Eccentric

Data Source

PatentEP2228203B1Mechanical forming press
Publication Date: 2015.09.09 ANDRITZ TECH & ASSET MANAGEMENT GMBH
  • EP2228203B1 patent drawingFigure 1

AI summary

The press has a press gearbox (1) on which a press ram is mechanically coupled with a press drive (2), where the press drive comprises an electrical servo motor. The press gearbox has continuously variable transformation ratio between a drive shaft (20) of the servo motor, and an output shaft (30) i.e. eccentric shaft, for the press ram, where the output shaft comprises an eccentric (32). The output shaft is eccentrically arranged with a counter gear (31) and coupled with the counter gear by a drag link assembly (3) of the press gearbox. An independent claim is also included for a method for operating a mechanical forming press.